1. Field of the Invention
The present invention relates to a substrate processing apparatus and a substrate processing method for applying a predetermined wet processing to a substrate surface by supplying a processing liquid to the substrate surface, and then, drying the substrate surface wet with the processing liquid. Substrates to be dried include semiconductor wafers, glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for plasma displays, substrates for FEDs (field emission displays), substrates for optical discs, substrates for magnetic discs, and substrates for magnet-optical discs.
2. Description of the Related Art
Numerous drying methods have already been proposed which aim at removal of a rinsing liquid adhering to a substrate surface after chemical processing using a chemical solution and rinsing processing using a rinsing liquid which may be pure water or the like. Known as one such method is a drying method which uses a liquid (low surface tension solvent) including an organic solvent component whose surface tension is lower than pure water such as IPA (isopropyl alcohol). There is a drying method described in JP-A-9-38595 for instance as such a drying method. In a substrate processing apparatus which executes this drying method, after hydrofluoric acid treatment of a substrate surface, pure water is supplied to the substrate surface and cleaning processing (rinsing processing) is accordingly attained. Following this, IPA is supplied to the substrate surface without any break after the end of the supply of pure water or from the middle of the supply of pure water. In consequence, IPA is dissolved in pure water which is present on the substrate surface, and replaces pure water. The substrate is rotated at a high speed thereafter, which removes IPA from the substrate surface and the substrate surface is dried.
Further, according to a resist developing method described in JP-A-3-209715, the substrate surface is dried while the amount of micro foreign matters present on the substrate surface is reduced in the following manner. First, pure water is supplied to the substrate after development of a resist, thereby performing pure water cleaning (rinsing processing). After this, pure water containing IPA at the capacity ratio of about 10% (IPA solution) is supplied to the substrate, whereby the substrate is cleaned. This is followed by spin drying of the substrate while rotating the substrate at a high speed.